Where is the oil temp sensor?

[ac427]

12617508003 Oil level sensor aka Hella 6PR 007 868-031

[ac427]

Somewhat related, but wasn't there some thing about how the oil temperature reading is 'fake' and based on coolant temperature? Or am I confusing it with something else?

That's true. The dashboard reading on the gauge is calculated from a few factors including air inlet temp.

The is an oil/coolant temperature sensor in the coolant return pipe.

[heinzboehmer]

Oh yeah, that's an important distinction that I failed to make earlier. The raw data coming from the DME (usually through the OBD port) is fairly accurate in my experience. However, as stated above by others, the oil temp gauge does not correspond directly to the oil temp. Some other stuff is factored in too.

Again, straight from TIS:

The oil temperature displayed in the instrument cluster is determined by a model that is based on the coolant temperature at the cooler outlet, the oil temperature from the oil level transmitter, the coolant temperature of the engine, the ambient temperature and the intake-air temperature.

[BBRTuning]

The gauge in the cluster is off but the actual reading from the ECU is accurate.

I ran an aftermarket oil temp gauge with the sender that replaced the oil pan plug. The aftermarket gauge read pretty much the same as the ECU data on my AiM Solo...within +/- 5 degrees every time I checked it. When I pull oil temp data the ECU is recording some significant changes during a lap, up to 30 degrees in some cases. I'd expect the oil temp needle in the OE gauge to move a lot more but I've never observed much movement. It's a track car, so I usually only check the gauges when I'm on a straight.

I deleted the aftermarket gauge since it was mostly redundant with the AiM solo DL. But I'd be confident that the OE gauge would tell me when the oil temps are getting hot and I should back off. I just would rather have a little more info to tell me when things are starting to get hot so I can back off a little earlier to reduce the likelihood of an issue.

Here is a video with oil temp data. The data is from the AiM Solo D-CAN connection so its from the ECU. You can kind of see the gauge in the cluster

Reading the value directly off the sensor is accurate but only if the car is stationary/minimal G force for an extended time. It doesn't work on track due to the large amount of oil slosh, the sensor readings will be all over the place and read artificially high. The reading on the dash is not only a calculation from multiple inputs but also is smoothed to prevent this. Still, installing a proper NTC style sensor in the sump or the hot side of the filter housing will give you a true as well as stable reading.

[Mike RT4]

These are the figures I am getting (see also last page for on track figures):

https://nam3forum.com/forums/forum/main-forum/member-build-journals/201449-2003-uk-m3-csl/page3